System for the transmission of intelligence.



V R. A. HEISING. SYSTEM FOR THE TRANSMISSION OF INTELLIGENCE.

APPLICATION man NOV. 14. 1914.

1,137,315. Patented Apr. 27, 1915.

Wvfi fl W/fnesses: /nvenfor: 62997 01451, Raymond/4. f/e/s/nq WWW. y M E A/T y.

UNITED STATES PATENT OFFICE.

RAYMOND A. HEISING, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN" ELECTRIC COMPANY, OF NEW YORK,

N. Y., A CORPORATION OF ILLINOIS.

SYSTEM FOR THE TRANSMISSION OF INTELLIGENCE.

Specification of Letters Patent.

Patented Apr. 27, 1915.

Application filed November 14, 1914. Serial No. 872,105.

To all whom it may concern Be it known that I, RAYMOND A. HEISING, a citizen of the United States, residing at East Orange, in the county of Essex and State of NewJersey, have invented certain new and useful Improvements in Systems for the Transmission of Intelligence, of which the following is a full, clear, concise, and exact description.

This invention relates to systems for the transmission of intelligence in which the amplitude of successive oscillations of high frequency are varied in accordance with the lower frequency forms of the message ,delivered. Its object is to simplify the mechanism and increase the effectiveness of the apparatus required for the production of the modulated oscillations.

To these ends the invention embodies two thermionic repeaters in series, one of which has its input connected in circuit with a generator of high frequency oscillations, and the other its input in circuit with a telephone transmitter or other device for sending a message.

The invention is adapted for embodiment in systems of wireless telegraphy and telephony and in so-called high frequency wire systems of telephony and in general wherever a receiving device is rendered sensitive to signaling impulses or waves of low frequency by means of sustained electric or electromagnetic waves of high frequency transmitted from the sending station.

The two thermionicnrepeaters in series, above referred to, are preferably of the audion type. By varying the potential in the input circuit of one of the repeaters, as for example, by connecting a transmitter or other device for sending a message in circuit with one of the electrodes, say the grid of the audion, the sustained oscillations, it has been found, are then modulated in accordance with the message to be sent. The message may be received or recorded in anydesired manner at the distant station.

The invention will be set forth in the following nection with the accompanying drawing, which illustrates a system' of circuits embodying the invention.

Referringjo the drawing, the audions 1 and 2, the elements of whiclf are inclosed in evacuated vessels or vacuum tubes as usual,

detailed description'taken in con- 1 are connected in series, that is to say, the two audions have a common'output circuit. This common output circuit includes the heated filament or cathode 3 and the output anode or plate 4 of the audion 1 and the heated filament 3' and the output anode or plate 4 of the audion 2. Included in this common output circuit may be located 'a battery 5.

The input circuit of the audion 1 includes the heated filament or cathode 3 and the input electrode or grid 6. United with the input circuit of the audion 1 is a source 10 of high frequency potential. The input circuit of the audion 2 includes the heated filament or cathode 3' and the input electrode or grid 6'. United with the input circuit of the audion 2 is a source of low frequency current, as for example, a telephone line or other apparatus 11 suitable for producing low frequency potential variations.

Included in the common output circuit of the two audions is one of the windings 7 of a transformer, the other winding 8 of which leads to the antenna of a wireless system, or to the line of a wire system according to the particular use to which the apparatus is put.

The operation of this system is as follows: The audion 1 is rendered active by the heated filament 3, which emits a stream of negative ions across the space intervening between it and the positively charged plate 4. This stream passes through the interspaces of the grid 6. The battery tends to maintain a steady flow of current in the output circuit, which includes the ionized space between the plate 4 and the filament 3. The flow of current across the ionized space, however, is not steady but is caused to fluctuate at a Very high frequency by reason of the high frequency potential connected with the input circuit of the audion. The high frequency currents in the output circuit are transmitted by the repeating coil 9 into the line or antenna to which the secondary winding 8 may be connected.

By means of the telephone transmitter or other sending de 'ice, connected in the input circuit of the audion 2, the amplitude of the sustained oscillations in the common output circuit of the two audions is modified or modulated in accordance with sound waves which are of-the high frequency vacuum tube 1, whose grid potential has not been changed, the voltage acrossthe high frequency vacuum tube will be lowered and the space current decreased. It thus appears that the speech vacuum tube A 2 acts as a voltage changer for the high frequency vacuum tube 1.

Thus, each pulsation of potential, caused by speaking through a transmitter connected in circuit with the input of the speech vacuum tube 2, is effective in producing a corresponding variation in the amplitude of oscillations of current and therefore of energy in the output circuit common to two vacuum tubes and likewise in the line or antenna.

VV hat is claimed is:

1. The combination with two thermionic repeaters connected in series and having a common output circuit, of a source of high frequency potential united with the input circuitfof one of said repeaters, a source of low frequency potential variations united I with the input circuit of the other repeater, and message transmitting means united with the common outputcircuit of said repeaters.

2. The combination withtwo evacuated vessels and means, including a cathode each vessel, for producing a state of ionization in said vessels; of an input anode and an output anode in each of said vessels; a common output circuit including said output anodes in series; an independent input circuit for each of said vessels, each of said input circuits being connected to the corresponding input anode; means connected with one of said input circuits for producing high frequency potential therein; and means connected with the other input circuit for producing low frequency potential variations in said last mentioned input circuit.

3. The combination with two audions having a common output circuit and each having an independent input circuit, of a source of high frequency potential united with the input circuit of one of said audions, a source of low frequency potential variations united with the input circuit of the other audion, and message transmitting means united with the common output circuit of said audions. I

In witness whereof, I hereunto subscribe my name this 13th day of Noige mber, A.: D.

RAYMOND A fiElslNG. Witnesses: a

E. EDLER, K. L. STAHL. 

